Mold for casting metals



Jan. 18, 1927. 1,615,086

0 JUNKER MOLD FOR CASTING METALS Flled July 23 1925 INVENTOR 1 I BY! T WQRNEC g Patented I 18 19 27.

UNITED STATES OTTO JUNKEB, OF STOLBERG, I

morn non cns'rme METALS.

Application fledjuly 28, 1925, Serial No. 4,468, and in Sweden larchv10, 1924.

This invention relates to chill molds and more particularly to chillmolds with water circulation for casting metalplates for use in rollingmills. Y

,Chill molds with water circulation have been known :Eor a considerabletime. They have the drawback that the metal plates cast therein areconsiderably inferior to those cast in sand'mglds, i. e. metal platescast in a bad heat cohtlucting material. 7 In water cooled chill'n'ieldsthe outer layer of the liquid meta Ibe'co'mes chilled and great dif--ierences in the grain and consequentl' great stressesoccur during thesetting of t e cast )late, which exhibit very harmful effects duritsfurther treatment.

' order to avoid this drawback, it has previously been suggested, tobring the cool'- ing fluid to a comparatively high temperature.

For this purpose, however, not only is it necessary to have recourse toa rather complex arrangement, but the metal molds are liable to wear outrapidly on account of thehigh temperature to which they are continuouslyexposed.

It has, moreover, been suggested to employ metal chill molds having thinwalls rovided with a hollow space filled with san around the thin wallsof the mold. I

The cooling in such chill'molds is still 1 slower than in commonsandmolds, but the cast, the chilling,

casting, although being free from stresses, ossesses a loose texture'anda rough surace in consequence of too slow a cooling.

The present invention enables these draw-v backs to be avoided andresults in the production of metal plates which are free from ,stressesand at the same time possess homo-. geneous and fine grained texture.The invention solves the problem by providing a.

chill 'mold in which the walls-so far as is concernedconsist of water.

. For this purpose, the two walls of the chill mold which contact withthe metal plate to be cast, are made of very thin sheet metaland wateris brought into contact with their rear sides; In this manner, achill-mold is obtained, in which the water, being a bad heat conductor,prevents any sudden,.deeply penetrating'chilling of the metal plate tobe onthe contrary, taking place as follows':-'-

The thin plates of sheet metal take up the first heat from the liquidmetaland produce,

by their heat absorptionan initial skin on the outermost layer of thecasting. This 'ing the first thin skin, has loeenheated, the

water cooling of the chill mold commences to i be efiective, that is tosay, the continuously renewed water behind the sheet metal causesfurther heat absorption. The drop of temperature between the material ofthe chill mold and the'metal to :be cast is ke t constant by saidcontinuous supply 0 fresh water. Dueto thefbad heat conductivity of Ithe water a casting is thus obtained having a uniform texture of mediumgram size over 1ts entire cross section. The outermost sk1n formed onthe casting is too thin to enable cracks penetrating deeply into thecasting, and stresses in the latter to occur..

One constructional form of the improved chill-mold is illustrated-by wayof examwhich:-

Figs. 1 and2 show the chill mold in front and side elevation,respectively, and

Fig. 3 shows a part cross-section on an enlarged scale on the line A--Aof Fig. 1.

The construction shown illustrates a double chill mold in which twometal plates may be cast simultaneously in the spaces a, a; The lateralwalls of each casting space are formed by verythin plates of sheet.metal b, for example sheets of cop er. The rear surfaces of these sheetsare in contact with flowing water. In this particular example acentral'water space c and two lateral water spaces (1 are provided, thelatter being situated ,in the two covers e of the chill mold. -Thewater-tight closure is effected by packings f. In order to revent the.thin sheets I) from bellying un er the pressure of the metal to be cast,they are supported rearwardly by ribs 9 provided on the mold.

Peculiar also is the arrangement. of the water supply and discharge,which are effected by a system of pipes rigidly connectedto the chillmold, 1. e. the'water supply takes place through the pipe h and thewater discharge through the pipe i.- The sup- 7 plypipe h terminates ina tubular cross piece is carryin two hollow hinge heads I or theoscillabde covers. e of the mold. The water supply to the middle'space 0of ple in the accompanying drawings in 80 the mold takes placev by wayof the channel m. 011 the other hand, the water supply to the two coverspaces 05 is effected through the hollow hinges Z and the bent tubes n.Each of these latter is provided with an elastic connecting member 0adapted to yield when the closing of the chill mold is effected by meansof the presser screws p.

While the water supply takes place at the lower part of the chill mold,the water discharge is eflected at the upper part of the mold by meansof a similar system of pipes, as will be understood from Figs. 1 and 2,in. order to ensure the entire filling of the water spaces.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is A double wall metal mold for casting, metals, comprisingin combination thin innerwalls which are smooth on bot-h sides, andthick outer walls provided with ribs on their inner sides, said ribsbeing disposed in contact with the inner walls thereby to support thelatter and prevent outward bulging thereof.

In testimony whereof I have signed my name to this specification.

OTTO JUNKER.

